Columbus NanoWorks (CNW) proposes research leading to the commercialization of custom magnetic nanoparticle reagents for the detection of cancer cells from various sources such as bone marrow and peripheral blood. Cell separation is becoming increasingly commonplace for researchers and clinicians who isolate rare cells from complex cell populations to understand how cells function in different environments or to diagnose disease occurrence, recurrence or progression. Complex mixtures and searches for small variations in cell samples require new techniques that provide exquisite sensitivity with high throughput;therefore, advances in cell separation technology must allow the researcher to find low percentage cells of interest, as well as purify them to allow for accurate assessment of biological relevance. In Phase I research CNW demonstrated the manufacture of magnetic nanoparticles that were uniform in size within a range of 50 to 70nm, had a ligand density of 2 to 5 ug/ml Fe particles and elicited a magnetophoretic mobility of immunomagnetically labeled cells an order of magnitude greater than commercially available magnetic reagents. The aforementioned criteria defining magnetic particles achieved in the Phase I application, allowed the enrichment of 1 tumor cell in 107 total cells with an average recovery of 74.1% of spiked tumor samples, as well as an average 3.21 log10 depletion of contaminating cells in the flow-through magnetic sorter known as the Quadrupole Magnetic Sorter (QMS). Phase II research thus calls for the design and commercialization of magnetic reagent kits specific for QMS applications involving cancer cell enrichment. CNW will (1) scale up processing efforts to obtain a 50 fold increase over current process techniques;(2) establish procedures and practices which assure consistent control of nanoparticle size and magnetic properties;(3) develop protocols for CNW cell enrichment kits for use in the commercial magnetic flow sorter, QMS;and (4) beta testing of protocols using breast cancer patients and head and neck cancer patients. The proposed Phase II end items are customized magnetic reagent kits specific for the QMS system that will allow the enrichment of cancer cells from various blood sources such as bone marrow and peripheral blood. Specifications of the particles will provide a greater than 70% recovery of desired cells, as well as a 4 log10depletion of contaminating cells. The resultant enriched fraction using CNW nanoparticles in the QMS system will provide a quality-purified product for further downstream processing and subsequent molecular analysis. The goal is for CNW customized reagents to become an integral part of gold standard testing in the current pathology repertoire. Columbus NanoWorks is a magnetic nanoparticle reagent company that provides reagents for magnetic cell separation. In this application we will develop magnetic reagent kits as commercial reagents for the Quadrupole Magnetic Sorter (QMS) system. In the past, commercial magnetic nanoparticles used in the QMS system have provided sub-par results with respect to purity and recovery of desired cells. Columbus NanoWorks demonstrated in their Phase I application that reagents custom designed for the QMS were able to achieve an average 3.21 log10 depletion of contaminating cells as well as an average recovery of 74.1% of tumor cells from control samples. We believe that CNW's custom reagent kits for the QMS system will provide more predictable, reproducible results from sample to sample.